Marine Biology Commons^™

Chemical And Isotopic Characterization Of Size-Fractionated Organic Matter From Cryoturbated Tundra Soils, Northern Alaska, Chunhao Xu, Laodong Guo, Chien-Lu Ping, Daniel M. White, Thomas D. Lorenson

Faculty Publications

Recent studies indicate a second layer of organic matter often accumulates in the lower active layer and upper permafrost in arctic tundra soils as a result of cryoturbation. In this study, cryoturbated organic matter was characterized using a combination of physical size fractionation and modern analytical techniques for elemental composition (C and N), stable isotopes (delta(13) C and delta(15)N), radiocarbon content (Delta(14)C), and molecular fingerprinting (pyrolysis-gas chromatography/mass spectrometry, Py-GC/MS). The results indicated that cryoturbated organic matter could be highly bioavailable. Soil organic matter (SOM) associated with fine sand particles was considered to be the organic carbon pool most sensitive to …

On The Mechanisms Of Episodic Salinity Outflow Events In The Strait Of Hormuz, Prasad G. Thoppil, Patrick J. Hogan

Faculty Publications

Observations in the Strait of Hormuz (26.26 degrees N, 56.08 degrees E) during 1997-98 showed substantial velocity fluctuations, accompanied by episodic changes in the salinity outflow events with amplitude varying between 1 and 2 psu on time scales of several days to a few weeks. These events are characterized by a rapid increase in salinity followed by an abrupt decline. The mechanisms behind these strong pulses of salinity events are investigated with a whigh-resolution (similar to 1 km) Hybrid Coordinate Ocean Model (HYCOM) with particular reference to the year 2005. In accordance with the observations, the simulated salinity events are …

The Effects Of Climate Variability On The Structure Of The Phytoplankton Community In Tumaco Bay, Colombia, Ingrid Garcia-Hansen Honkala

Dissertations

Spatiotemporal variability in the diatom and dinoflagellate community structure and chlorophyll a (chl a) concentrations in Tumaco Bay during the 1993-2005 period was related clearly to seasonal and interannual variability in environmental conditions due to the migration of the Inter-tropical Convergence Zone (ITZC) and the influence of El Nino Southern Oscillation (ENSO) events. A total of 134 species of diatoms that belong to 57 genera, and 78 species of dinoflagellates that belong to 25 genera were identified during the survey. The diatom community was the dominant group in the waters of the bay, being the most abundant with the greatest …

Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio

Dissertations

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm …

Historical Account Of The Two Family-Group Names In Use For The Single Accepted Family Comprising The "Fish Blood Flukes", Stephen A. Bullard, Kirsten Jensen, Robin M. Overstreet

Faculty Publications

The family-group name for the "fish blood flukes" is unstable, with both "Aporocotylidae Odhner, 1912" and "Sanguinicolidae von Graff, 1907 "in use for the single family. Although "Sanguinicolidae von Graff, 1907" (or "Graff, 1907") has been a widely-accepted family-group name for the fish blood flukes subsequent to Yamaguti's 1954 and 1958 synoptical publications ("Systema Helminthum"), a critical examination of the relevant literature, much of it published in German during 1900 through 1926, reveals that "Aporocotylidae Odhner, 1912" is the earliest available family-group name for these flukes. The name Aporocotylidae, moreover, was in wide usage by alpha taxonomists before 1954 and …

The Influence Of Habitat And Fishing On Reef Fish Assemblages In Cuba, Gaspar Gonzalez-Sanson, Consuelo Aguilar, Ivet Hernandez, Yureidy Cabrera, R. Allen Curry

Gulf and Caribbean Research

The abundance of selected fish species was estimated using the stationary visual census technique in the northwestern region of the Cuban shelf. A total of 26,809 individuals of 32 species were counted in 1,172 stationary point censuses made at 10 reef sites along the coast. We found that the abundance patterns were most probably the consequence of the presence/absence of mangroves and seagrass beds in adjacent lagoon areas. A second factor influencing the spatial variation appeared to be overfishing on an east-west gradient, with lower abundances of commercially targeted species near Havana City in the east.

Abundance And Distribution Of Two Species Of Squilla (Crustacea: Stomatopoda: Squillidae) In The Northern Gulf Of Mexico, Jennifer L. Wortham

Gulf and Caribbean Research

Stomatopods (mantis shrimps) are predatory benthic crustaceans. Mantis shrimp in the genus Squilla are frequent bycatch animals unintentionally collected in conjunction with the shrimp fishery in the Gulf of Mexico (GOM). Their carcasses are discarded instead of being retained for human consumption, fish meal, or other protein-based food products. The size, depth, salinity, and temperature distributions of these species, as well as their abundance based on gender, were examined to gain biological information that would be necessary if a fishery were to develop in the GOM. I collected samples (n = 2,854) of Squilla empusa and Squilla chydaea in the …

Seagrass Loss In Belize: Studies Of Turtlegrass (Thalassia Testudinum) Habitat Using Remote Sensing And Ground-Truth Data, Gary R. Gaston, Cole Easson, Greg Easson, Justin Janaskie, M.A. Ballas

Gulf and Caribbean Research

Spatial and temporal change in turtlegrass (Thalassia testudinum) habitat of the South Water Caye Marine Reserve (SWCMR) in Belize were analyzed using satellite images backed up with ground-truth data. We had two pri-mary objectives. First, we wanted to determine areal expanse of seagrass across a large area (~12 km by 3 km) of the SWCMR, and address its change over time. We used paired satellite images taken during 2001 and 2005 to determine coverage by seagrass and measure temporal variables. These analyses recorded an overall seagrass loss of 1.8% (52.3 ha) during the 4 yr period. Secondly, we …

Determining Salinity-Tolerance Of Giant Salvinia Using Chlorophyll Fluorescence, Patrick D. Biber

Gulf and Caribbean Research

Salvinia molesta Mitchell, a floating invasive aquatic plant, is one of the top 10 worst invasive aquatic weeds in the world. It was discovered in the lower Pascagoula River in 2005 and evidence suggests that this non-native species is spreading along the northern Gulf of Mexico. These plants exhibit rapid growth and nutrient uptake rates, allowing them to out compete other plants in similar habitats. Distributional observations suggest that non-native S. molesta is able to survive in salinities of up to 7 ppt in the lower Pascagoula River. The response of S. molesta to three salinity levels (0, 5, 10 …

First Records Of The Seagrass Parasite Plasmodiophora Diplantherae From The Northcentral Gulf Of Mexico, Allison K. Walker, Jinx Campbell

Gulf and Caribbean Research

Plasmodiophora diplantherae is known to occur throughout the pantropical distribution of its host, the seagrass genus Halodule. However, records in the subtropical region are limited to Tampa Bay, FL where it was detected once during an examination of herbar-ium specimens of H. beaudettei collected in December 1951 (den Hartog 1965) and to Fort Pierce, FL where it was collected once infecting H. wrightii (Braselton and Short 1985). This communication represents the first report of this parasite from Mississippi and Louisiana in the northcentral Gulf of Mexico (GOM).

A Comparison Of Fish Populations In Shallow Coastal Lagoons With Contrasting Shoalgrass (Halodule Wrightii) Cover In The Northcentral Gulf Of Mexico, Just Cebrian, Glenn A. Miller, Jason P. Stutes, Adrienne L. Stutes, Mairi E. Miller, Kate L. Sheehan

Gulf and Caribbean Research

A number of studies have examined the effects of reduced seagrass cover on local fish populations (e.g., Heck et al. 1989, Ferrell and Bell 1991, Hughes et al. 2002 and more), but few of those studies have focused on shoalgrass (e.g., Tolan et al. 1997, Rydene and Matheson 2003). We present a preliminary comparison of fish populations in three shallow coastal lagoons in the northcentral GOM that have varying levels of shoalgrass cover. Namely, we compare (1) abundances of individual species and the entire fish population, (2) fish population diversity, and (3) length-frequency distributions of the most abundant species.

Age Estimates Of Two Large Misty Grouper, Epinephelus Mystacinus (Serranidae) From Bermuda With A Comparison Of The Age Of Tropical Groupers In The Western Atlantic, Brian E. Luckhurst, John M. Dean

Gulf and Caribbean Research

Misty grouper are known to attain at least 54 kg and 115 cm total length (TL) (Heemstra and Randall 1993) although a maximum size of 160 cm TL is reported (Appeldoorn et al. 1987, cited in www.FishBase.com). Recently, two specimens (152 and 157 mm TL) were landed by commercial fisherman from the edge of the Bermuda platform, providing documentation of the maximum size which may be attained by this species. There are no age and growth studies on misty grouper (Heemstra and Randall 1993; www.FishBase.com). Therefore, the age data presented here, although not validated, represent the first estimates of maximum …

Macrofauna Associate With Ungrounded Prop Roots Of Rhizophora Mangle In Veracruz And Quintana Roo, Mexico, Kathryn D. Tunnell, Kim Withers

Gulf and Caribbean Research

The prop roots of the red mangrove (Rhizophora mangle) provide a solid substrate for diverse assemblages of marine organisms in areas typically characterized by soft bottoms (Bingham 1992, Farnsworth and Ellison 1996). Macrobenthic communities of mangroves have received little attention compared with other components of the ecosystem, largely due to sampling difficulties (Lee 2008). Mangrove root epifauna are likely used by predatory fish, especially juveniles. Thus, these organisms have the potential of being important links between mangroves and adjacent ecosystems. The fauna associated with red mangrove prop roots along Mexican Gulf of Mexico (GOM) and Caribbean shorelines has …

Morphological Characteristics Of Early Life History Stages Of The Blue Crab, Callinectes Sapidus Rathbun, From The Northern Gulf Of Mexico With A Comparison Of Studies From The Atlantic Seaboard, Kenneth Stuck, Harriet Perry, Darcie Graham, Richard W. Heard

Gulf and Caribbean Research

Zoeae, megalopae, and early crab stages of Callinectes sapidus Rathbun, 1896 were described from the northern Gulf of Mexico (nGOM). Observations during this study were based on larvae reared in the laboratory through the early crab stages and on megalopae and early crab stages collected in the wild. Gulf of Mexico data are compared with similar information for the southeast Atlantic coast of the United States. Size and setation of C. sapidus larvae reared from nGOM stocks were different than those in published descriptions of larvae reared from Atlantic populations. Seasonal differences in size were noted in both reared and …

Note On The Natural And Cultural History Of Hurricane Balls, Joyce M. Shaw

Gulf and Caribbean Research

Hurricane balls are natural phenomena of tropical storms and hurricane winds and waves and are found along the shoreline. Gunter Library at the Gulf Coast Research Laboratory (GCRL) is home to a small collection of hurricane balls which were found along the shore lines of barrier islands and marsh beaches by GCRL staff over the years. Hurricane balls come in many sizes, and large balls can be slightly larger than a standard basketball of 24.8 cm diameter (USA Basketball 2001). Large balls in the Gunter Library collection range from 34.5 cm diameter (from 1969 Hurricane Camille) to 53.5 cm diameter …

Satellite-Detected Fluorescence Reveals Global Physiology Of Ocean Phytoplankton, Michael J. Behrenfeld, T.K. Westberry, Emmanuel Boss, R.T. O'Malley, D.A. Siegel, Jerry D. Wiggert, B.A. Franz, G.C. Feldman, S.C. Doney, J.K. Moore, G. Dall'olmo, A.J. Milligan, I. Lima, N. Mahowald

Faculty Publications

Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of …

Genetic Variation For Carcass Quality Traits In Cultured Sea Bass (Dicentrarchus Labrax), Eric A. Saillant, Mathilde Dupont-Nivet, Marie Sabourault, Pierrick Haffray, Stanislas Laureau, Marie-Odile Vidal, Béatrice Chatain

Faculty Publications

Genetic parameters for carcass quality traits were estimated in 27 families of sea bass (3 dams x 9 sires factorial mating design), raised mixed in the same tanks starting before hatching. O. spring parentage was determined a posteriori using 6 microsatellite loci. Carcass quality traits were recorded at 818 days post fertilization (mean standard length: 32.6 +/- 3.1 cm). Genetic parameters were estimated from the sire half sib variance and covariance components. Heritability of body weight (BW) and carcass processing traits (standardized to body weight) percent head weight (Head%), percent viscera weight (Viscera%) and percent visceral fat weight (VisceFat%) were …

Topographic Effects On The Path And Evolution Of Loop Current Eddies, Kyung Hoon Hyun, Patrick J. Hogan

Faculty Publications

Eddy-topography (ET) interactions are important in determining the path and evolution of oceanic eddies, including Loop Current Eddies (LCE) in the Gulf of Mexico (GOM). We use the Hybrid Coordinate Ocean Model and satellite altimetry data to investigate the ET interactions and the impact on LCE pathway evolution in the GOM. Satellite altimetry reveals that LCEs translate dominantly westward in the central GOM and strongly collide and reflect against topography near the continental slope in the northern and western GOM. The result is the frequent generation of an anticyclone-cyclone (AC) pair in conjunction with the LCEs. In the absence of …

Gene Expression Profiles As Molecular Indicators Of Dissolved Oxygen Stress In Grass Shrimp Palaemonetes Pugio Holthuis 1949, Tiandao Li

Dissertations

Occurrence and severity of hypoxia is increasing in coastal and estuarine environments, and recovery of impacted habitats and living resources is slow. Detection of early biological effects of hypoxia is needed for timely remedial action to be taken. The overall objectives of this research was to develop molecular indicators of dissolved oxygen stress to assess the biological impact of hypoxia in coastal estuaries and validate their use through a combination of laboratory and field studies. To achieve these goals, grass shrimp, Palaemonetes pugio, oxygen-sensitive and hypoxia-tolerant species abundant in estuarine systems, were exposed to hypoxia under controlled laboratory conditions, and …

Yellow Head Virus: Transmission And Genome Analyses, Hongwei Ma

Dissertations

Yellow head virus (YHV) is an important pathogen to shrimp aquaculture. Among 13 species of naturally YHV-negative crustaceans in the Mississippi coastal area, the daggerblade grass shrimp, Palaemonetes pugio, and the blue crab, Callinectes sapidus, were tested for potential reservoir and carrier hosts of YHV using PCR and real time PCR. The YHV replicated in the daggerblade grass shrimp, and was still detectable on 36 d post-inoculation, causing 8% mortality after injection. However, YHV did not replicate in the blue crab. These data suggest that the daggerblade grass shrimp could act as a reservoir host for YHV. Storage conditions of …

Leucon (Crymoleucon) Rossi, A New Species (Crustacea: Cumacea: Leuconidae) From The Shelf Waters Of The Ross Sea (Antarctica), With A Key To The Genus Leucon South Of 60°S, Peter Rehm, Richard W. Heard

Faculty Publications

A new leuconid cumacean, Leucon (Crymoleucon) rossi n. sp., is described from depths of 84 to 458 m in the Ross Sea off the Victoria Land coast. Leucon rossi n. sp. is distinguished from other members of the genus by a combination of characters including 1) a blunt, horizontally directed pseudorostrum) Without a distinctly protruding siphon; 2) strongly developed antennal notch; 3) entire dorsomedian margin of carapace appearing serrate, armed with 14 to 19 anteriorly Curved spines in female (up to 21 in subadult males); 4) a small, but distinct, spine behind the frontal lobe; and 5) the uropodal peduncle …

A Competitive Hybridization Model Predicts Probe Signal Intensity On High Density Dna Microarrays, Shuzhao Li, Alex Pozhitkov, Marius Brouwer

Faculty Publications

A central, unresolved problem of DNA microarray technology is the interpretation of different signal intensities from multiple probes targeting the same transcript. We propose a competitive hybridization model for DNA microarray hybridization. Our model uses a probe-specific dissociation constant that is computed with current nearest neighbor model and existing parameters, and only four global parameters that are fitted to Affymetrix Latin Square data. This model can successfully predict signal intensities of individual probes, therefore makes it possible to quantify the absolute concentration of targets. Our results offer critical insights into the design and data interpretation of DNA microarrays.

Seasonal Variations In Nutrient Concentrations And Speciation In The Chena River, Alaska, Yihua Cai, Laodong Guo, Thomas A. Douglas, Terry E. Whitledge

Faculty Publications

To better understand the seasonal controls on nutrient abundances, speciation, and fluxes in a watershed underlain by discontinuous permafrost, we collected water samples biweekly from the Chena River during 2005-2006 to measure inorganic and organic N, P, and Si in dissolved and particulate phases. Nitrate concentrations were low (8-14 mu M) during the winter and summer dry seasons but were elevated during the spring freshet (15-24 mu M). Ammonium varied from 8 to 13 mu M during the winter but dropped dramatically during the ice-open season to 0.1-3 mM. Phosphate was very low throughout the year (ranging from 0.03 to …

Review Of The Genus Polycheria Haswell, A Symbiotic Group Of Amphipods (Crustacea: Dexaminidae) With Descriptions Of New Species From Florida, The Caribbean Sea, And The Indo-Pacific Region, John Milton Foster

Dissertations

Systematics and taxonomy of the dexaminid amphipod genus Polycheria Haswell (Dexamindae: Amphipoda), whose members are cosmopolitan associates of tunicates and sponges, are confused. This is due in large part to the many inadequate and incomplete descriptions and poorly some executed illustrations, especially for the early studies on the group. Previously, 22 nominal species or forms have been described or designated in the literature. The purpose of this study is to critically review and clarify the systematics of this enigmatic genus. Based on personal collections and on specimens from museums, five new species are designated and 22 species or forms are …

Satellite Assessment Of Bio-Optical Properties Of Northern Gulf Of Mexico Coastal Waters Following Hurricanes Katrina And Rita, Steven E. Lohrenz, Wei-Jun Cai, Xiaogang Chen, Merritt Tuel

Faculty Publications

The impacts of major tropical storms events on coastal waters include sediment resuspension, intense water column mixing, and increased delivery of terrestrial materials into coastal waters. We examined satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) ocean color sensor aboard the Aqua spacecraft following two major hurricane events: Hurricane Katrina, which made landfall on 29 August 2005, and Hurricane Rita, which made landfall on 24 September. MODIS Aqua true color imagery revealed high turbidity levels in shelf waters immediately following the storms indicative of intense resuspension. However, imagery following the landfall of Katrina showed relatively rapid return of …

Pan-Arctic Patterns In Black Carbon Sources And Fluvial Discharges Deduced From Radiocarbon And Pah Source Apportionment Markers In Estuarine Surface Sediments, Marie Elmquist, Igor Semiletov, Laodong Guo, Örjan Gustafsson

Faculty Publications

A pan-arctic geospatial picture of black carbon (BC) characteristics was obtained from the seven largest arctic rivers by combining with molecular combustion markers (polycyclic aromatic hydrocarbons) and radiocarbon ((14)C) analysis. The results suggested that the contribution from modern biomass burning to BC ranged from low in the Yukon (8%) and Lena (5%) Rivers to high in the Yenisey River (88%). The Mackenzie River contributed almost half of the total arctic fluvial BC export of 202 kton a(-1) (kton = 10(9) g), with the five Russian-Arctic rivers contributing 10-36 kton a(-1) each. The (14)C-based source estimate of fluvially exported BC to …

A Systematic And Taxonomic Review Of The Family Pseudotanaidae (Crustacea: Peracarida: Tanaidacea) Based Primarily On Morphometry Cladistic Analyses, Jerry Alan Mclelland

Dissertations

Species of the tanaid family Pseudotanaidae, established by Jurgen Sieg in 1973, have been reported from all the world's oceans in depths ranging from near the surface to below 6,000 m. The family currently consists of 46 characteristically small tanaidomorph species residing in two subfamilies, the Cryptocopinae (seven species) and the Pseudotanainae (39 species). Members of the more ancestral Crytocopinae differ from the Pseudotanainae by having females with four rather than three antennule articles and a complete separation of the maxilliped endites. The primary objective of this study was to test the hypothesis that the current structure of the family …

Evaluating Vascular Plant Composition And Species Richness On Horn Island, Mississippi, Using Passive And Active Remote Sensing In Conjunction With Ground Based Measurements, Kelly Lynn Lucas

Dissertations

Barrier island vegetation is subjected to chronic abiotic stressors combined with periodic storm events that favor species adapted to harsh environments. These islands are the first landforms to be affected by changes in coastal subsidence and sea-level rise. Evaluating changes in vegetation is important for understanding the impact of global climate change on coastal environments.

This study assesses vegetation composition and plant species richness on Horn Island, Mississippi using ground data in conjunction with remotely sensed spectral and LIDAR data. The goals of this research are to: 1) classify and map vegetation composition on Horn Island using hyperspectral and LIDAR …

Hurricane Katrina Winds Measured By A Buoy-Mounted Sonic Anemometer, Stephan D. Howden, David Gilhousen, Norman Guinasso, John Walpert, Michael Sturgeon, Les Bender

Faculty Publications

The eye of Hurricane Katrina passed within 49 n mi of an oceanographic observing system buoy in the Mississippi Bight that is part of the Central Gulf of Mexico Ocean Observing System. Although a mechanical anemometer failed on the buoy during the hurricane, a two-axis sonic anemometer survived and provided a complete record of the hurricane's passage. This is the first reported case of a sonic anemometer surviving a hurricane and reporting validated data, and it demonstrates that this type of anemometer is a viable alternative to the mechanical anemometers traditionally used in marine applications. The buoy pitch and roll …

Seasonal Variability Of The Observed Barrier Layer In The Arabian Sea, Pankajakshan Thadathil, Prasad Thoppil, R.R. Pao, P.M. Muraleedharan, Y.K. Somayajulu, V.V. Gopalakrishna, Raghu Murtugudde, G.V. Reddy, C. Revichandran

Faculty Publications

The formation mechanisms of the barrier layer ( BL) and its seasonal variability in the Arabian Sea ( AS) are studied using a comprehensive dataset of temperature and salinity profiles from Argo and other archives for the AS. Relatively thick BL of 20-60 m with large spatial extent is found in the central-southwestern AS ( CSWAS), the convergence zone of the monsoon wind, during the peak summer monsoon ( July-August) and in the southeastern AS ( SEAS) and northeastern AS ( NEAS) during the winter ( January-February). Although the BL in the SEAS has been reported before, the observed thick …